Great for men and women.

Usage

Short-sight:

Cover one eye with your hand and look at items six meters away while the other hand rotates the knob forward or backward until you can see the object.
2. Cover the other eye and repeat the above steps.
3. After the left and right eyes are adjusted separately, fine-tune the left and right rotation buttons with both hands to know the most suitable one.

Long-sight:

Note the object and leave a distance suitable for reading. Repeat the above steps.